Wednesday, May 15, 2013

City life hard on bird-parenting, too

Trying to raise youngsters in the concrete jungle of an urban environment is tough enough for human parents.
Now comes word via a university study that avian couples are facing the same dilemma in their efforts to rear their offspring as well.
The study comes from Bosie State University and is being reported by the American Bird Conservancy, a national bird advocacy group that also recounted on such other avian-related research projects as the width and depth of wild bird mortality caused by house cats.
In this latest notation the Conservancy says the Bosie State University focused on the impact of human activity on nesting American kestrels, once commonly called “sparrow hawks,” because of their diminutive size and their equally small prey.
By observing 28 kestrel nesting boxes alongside busy Interstate 84 in Idaho, scientists concluded the birds' suffered “elevated stress hormone” levels, a critical marker that saw many parenting birds “to abandon nests far more frequently.”
These nesting boxes were compared with counterparts placed along much lesser traveled roadways, the study reports, indicating that the rural life helped create much more mellow adult kestrels.
And, of course, a more mellow adult kestrel is a happier and more dedicated parenting kestrel, the summation of the report indicates.
“Birds evolved in an environment that was not dominated by humans,” the Conservancy quotes one the study's co-author-researcher, Julie A. Heath
 
 “In recent history, human roads and structures have left few areas untouched. We're just now trying to understand the consequences.”
And that understanding is leading to some solutions. Short of ripping up every highway or stop mowing the grass along them so kestrels no longer have ideal hunting habitat.
Instead, civil engineers are being tasked to incorporate designs that help lessen traffic noise, reduce speed limits where applicable, practical and possible.
“Many people think that since they see certain species of birds in urban environments, that they must have adapted to these unnatural surroundings,” said Conservancy president George Fenwick.
 
“However, this study certainly suggests that at least in some circumstances, the exact opposite is true.”
 
- Jeffrey L. Frischkorn

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